OP WASHINGTON, VOLUME XII, 1910. 177 



NOTES ON THE GEOMETRID GYPSOCHROA SHELL AT A 



GUEN. 

 BY H. M. RUSSELL. 



In Bade City, Florida, there was, in the fall of 1907, a 

 small strip of uncleared land where Amarantlius, poke-weed, 

 Spanish mulberry, etc., grew in abundance. On the poke- 

 weed the larvae of Gypsochroa sitellata Guen. fed in noticeable 

 numbers. 



On November 29, 1907, the writer again found these larvae 

 abundant on poke-weed at Orlando, Florida, almost every 

 plant having a few. The eggs were also abundant, and small 

 plants a foot high bore 9, 10, and 11, while on the older plants 

 there were many more. 



The notes which follow were made while working under 

 the direction of Dr. F. H. Chittenden, Bureau of Entomology, 

 United States Department of Agriculture. 



Since submitting this paper for publication Dr. H. G. Dyar 

 has called attention to the fact that he has described the egg 

 and stages I to IV, and given notes on the food-plant Pisonia 

 aculc.ata* In the publication cited the species is treated un- 

 der the name of Gypsochroa hcesitata Guen., the larvae having 

 been taken at Palm Beach and Key West, Florida. 



The eggs are generally laid on the underside of the leaf, 

 but in some cases are placed low down on the stem. They are 

 commonly laid singly, but sometimes two or three occur in 

 clusters. Besides being glued to the leaf, they have a thread 

 of silk to which they hang if dislodged. Eggs gathered on 

 December 3 hatched on the 8th or 9th of the month. As 

 these eggs when collected had a bright yellow color, they could 

 not have been laid very long. 



The egg is light orange color or a light whitish-j^ellow at 

 first. Gradually the yellow fades, 'and as the embryo develops 

 it becomes visible through the thin shell, making the egg 

 darker in color, so that it is light brown. The egg is ovate- 

 spheroid in shape, with a greatest diameter of 0.5 mm., and 

 is placed on one side. The surface with 24 X lens appears 

 dull, with faint reticulation. The larva escapes through a 

 hole at the anterior pole. 



December 3, 1907, the larvae were very abundant every- 

 where on poke-weed. The moth seems to pick out the young- 

 est plants to lay her eggs. The larvae start with the tender bud 

 at the top and strip the plant toward the base, leaving only the 



*Psyche, vol. ix, pp. 59-60, May, 1900. 



